Monsters which are monarchs (gnome king, Elvenking, etc) should be able to use thrones as summon engines. Such monsters would be able to, and would prefer to, spend their turn to “use” a throne on their current space instead of moving. This has a 2/3 chance of doing nothing, but a 1/3 chance of summoning d10 throne room monsters around the throne. This should never have the chance of making the throne vanish, but there should be some sort of limit on it so it can’t be abused for farming, possibly a cooldown similar to the one casters have for summon insects.

Their AI should be changed to make maximal use of this behavior: if they are already on a throne, awake, and hostile, they should attempt it at every opportunity to summon more allies. If they are not on a throne but there is one on the level unoccupied by another monarch, they should avoid engaging the player in combat and try to pathfind to the throne. Possibly they should still attempt to find and occupy thrones even if they won’t use them because they’re peaceful; that could create interesting interactions.